Thread-cutter for sewing-machines.



PATENTED APR. 25, 1905.

R. L.'LY;ONS.

THREAD CUTTER FOR SEWING MACHINES.

APPLICATION FILED MAY 5. 1902.

3 SHEETS-SHEET 1.

I lllllin lllllllll JIIIE i H 110.7%,21'2, PATBNTED APR. 25, 1905.

R. L. yons. THREAD CUTTER FOR SEWING MACHINES.

APPLICATION IIIiED MAY 5. 1902. t

3 SHEETS-SHEET 2.

I I W. i W ulna w illllll lll l lllil l Mill! l IIIIIIIHI mmmmn Ill .No.788,212. PATENTED APR. 25, 1905.

R. L. LYONS. THREAD CUTTER FOR SEWING MACHINES.

APPLICATION FILED MAY 5. 1902.

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UNITED STATES Patented April 25, 1905.

ROBERT L. LYONS, OF WVAL' HAM, MASSACHUSETTS.

THREAD-CUTTER FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 788,212, dated April25, 1905.

Application filed May 5, 1902. Serialllo. 105,913.

To all whom it may concern:

Be it known that I, ROBERT L. LYONS, a citizen of the United States,residing at Valtham, in the county of Middlesex and State ofMassachusetts, have invented certain new and useful Improvements in Thread-Cutters for Sewing-Machines, of which the following is aspecification, reference being had therein to.

the accompanying drawings.

This invention relates to improvements in sewing-machines, andparticularly to improvements in thread-trimming devices therefor.

The object of the invention is to automatically trim the shuttle-threadsbefore the work has been entirely drawn from the machine.

Another object of the invention is to draw out the shuttle-thread andsecure the cut end thereof at a distance from the path of the needle.

Other objects of the invention will be apparent from the description andclaims.

The invention thus also consists in a worksupport having provisionwhereby the shuttle-thread may be drawn away from the path of the needlewithout drawing said thread through the needle-hole and means forengaging and securing the shuttle-thread at or about the time the sameis severed.

So, also, the invention consists in such other novel features ofconstruction of parts as shall hereinafter be more fully described, andpointed out in the claims.

In the drawings, as illustrating the improved shuttle-thread cutter andholder in relation to other parts of a sewing-machine, Figure 1represents an end View of portions of a sewing-machine, illustratingthis invention, the work being partially drawn out. Fig. 2 represents afront view of portions of the same in the position for starting, butbefore the work is introduced. Fig. 3 represents a front view ofportions of the improved machine, partially in section, showing thepresser--foot in the elevated position and the positioner and cuttermembers for the needlethread in place as immediately after the drawingout of the work.

a plan view of portions of the machine-table and work-support, showingthe throat-plate slotted diagonally from the needle-hole and Fig. 4represents the slotted portion of the work-support with itsshuttle-thread cutter-and clamp. Fig. 5 is a detail view to illustratethe manner in which the cut end of the needle-thread is drawn down intothe work by the shuttlethread under the movement of the work to thepoint at which the shuttle-thread is engaged and cut.

Similar numbers of reference designate corresponding parts throughout.

In illustrating this invention I have shown the construction andarrangement of the parts adapted for the carrying out of the objectssought to be accomplished, these new parts being shown in relation tothe old and wellknown parts of the machine with which they cooperate. Itis herein understood that the parts which are omitted from the drawingsT are, or should be, of any well-known construction.

As shown in the drawings, the head 5 is of any usual construction and isfurnished with the ordinary presser-bar 6, vertically movable andpivotally connected with any usual (except as hereinafter stated)presser foot 7, this presser-bar 6 being depressed by the usual spring 8and being moved against the action of said spring by means of the lever9, pivoted in the head, the shaft 10 of which is fixed to said lever andis journaled in bearings of the head, the inner end of this lever beingengaged or connected with the presser-bar and the outer end of the leverbeing connected with any suitable means for depressing this end andelevating the inner end thereof, this means preferably consisting of theordi nary treadle, with which the lever 9 is connected by means of thechain 11.

The head 5 is provided with the usual takeup lever 12, mounted andactuated in the ordinary manner. It has also the guides 13, 14, and 15,over which the needle-thread is directed, and is furnished with thetension-disks 16 and 17, mounted on the post 18 and pressed together bythe spring 19 bearing against the nut 20 on said post and the surface ofthe disk 17. At the front or side of the head 5 is the guide 21. At thelower portion of the head is a member 22, preferably in fixed relationto the head and having the under bearing-surface 23, the extension ofwhich will be seen in Fig. 1 of the drawings. Adjacent to the front endof this member 22 is the needlebar 24, mounted for verticalreciprocation under the operation of the usual driving mechanism. Thisbar is shown as provided with a needle 25.

From the presser-bar 6 extends the stud 26, which Works through anopening in the head 5, and on the outer portion of this stud is fixedthe plate 27, having the upwardly-extending member 28, carrying thescrew-clamps 29 29, on which the slotted portion of the tension-releasewedge 30 is adjustably mounted, this wedge 30 being positioned to enterbetween the disks 16 and 17 and cause their separation as thepresser-bar is elevated.

On the stud-shaft 10, fixed on the head, is pivoted the thread-pullerplate 31, having the cam-slot 32, working over the stud 26, which studacts to swing the plate 31 as it, said stud, moves upward and as a stopagainst the end of said slot in the forward movement of the plate. Atthe upper end of this plate 31 is the adjustable screw-clamp 33,carrying the thread-puller 34, this puller being designed to be adjustedto work in relation to the action of the tension-release.

At the lower portion of the presser-bar is secured the bearing 35,preferably by means of the clamp 36, and on this bearing is rotatablethe cam-plate 37, having the cam edge 38. In perforations of this plateare adjustably secured the studs 39 and 40. In or on the stud 39 isadjustably mounted the shank of the needle-thread positioner 41, and inor on the stud 40 is ad justabl y mounted the shank of the needle-threadcutter member 42.

The needle-thread cutter member is herein shown in relation with acooperating cutter member 43, forming part of the arm 44 of the usualbutton-clamp 45, said arm being provided with the spring-plate 46; butwhere no button-clamp is used or desired this member 43 and thespring-plate 46 may be supplied to any suitable supporting portion ofany presserfoot.

The needle-thread a a is strung through the guide 13 over the guide 14,between the disks 16 and 17, to and under the guide 15, then through theperforation in the lifter-arm 12, through the guide 21, and through theeye of the needle 25.

The shuttle 47 is of the usual construction and operation, having anyordinary form of tension device or other well-known means for exertingmore or less resistance to the running out of the shuttle-thread b btherefrom.

The work-support preferably comprises a plate 48, having an opening 49from the front rearwardly approximately above the position of theshuttle, and a slot 50, extending diagonally from said opening andhaving converging sides. At one edge of said slot is secured a thincutting-blade 51, the cutting edge of which approximately follows theedge of the slot 50 or may overlap the same. In the opening 49 isremovabl y contained the throat-plate 52, furnished with the needle holeor passage 53 and with the slot 54 having converging sides, which slotwhen the throat-plate is in position registers with the slot 50 in theportion 48. It is, however, evident that the por' tions 48 and 52 aremade in separate parts merely as a matter of convenience and that theslot from the needle-hole to the cutter may be formed in one piece ofmaterial without changing the invention.

At the completion of the sewing the needle is in the position shown inFig. 2 of the d raw,- ings. The needle-thread, however, extends inpractically a straight line from the eye of the needle down through thework where the shuttle-thread extends through the last loop of theneedle-thread and lies somewhat in the approximately vertical positionbetween said loop and the shuttle. In making the last of a group ofstitches in this class of machine and on the last upward stroke of theneedle the needle-thread is drawn tight and draws the bight of theshuttle-thread to the forward portion of the group of stitches-that is,to the right-hand side as looking at Fig. 1 of the drawings and as thethreads are shown in full in Fig. 5 of the drawings. In removing thework from the machine it is necessary to raise the presser-foot, andthis is generally accomplished by depressing the outer end of the lever9. At the depression of the outer end of the lever 9 the presser-bar 6is raised, the initial result being to start the lifting of thepresser-foot and button-clamp and to force the wedge 30 between thedisks 16 and 17 of the needle-thread tension, thus releasing the threador reducing the frictional contact of the disks thereon. Practicallysimultaneousl y with such movement the threadpulle'r plate 31 is swungbackward and the thread-puller 34 engages the thread a a. and draws itfrom the direction of the guide 13, but has no effect on the threadbetween the needle and the work. Continuing, the lifting of thepresser-bar results in the lifting of the presser-foot to the pointshown in Fig. 3, and during this lifting the cam edge 38 of the cam 37is forced against the surface 23, thus from the shape of the cam edgecausing the cam to rock on its bearing to swing the threadpositioner 41and the cutter member 42 in succession across the path of the needle andbelow the point thereof. As the thread-positioner 41 swings between theneedle and the Work it engages this portion of the thread and carries itagainst the edges of the cutter member 43 and the spring 46, thuspositioning the thread for the subsequent nipping of the thread betweenthe cutter members 42 and 43 and between the upper inclined surface ofthe cutter member 42 and the curved portion of the spring 46, as shownin Fig. 3 of the drawings.

Attention is at this point called to the small amount of thread which isdrawn through the needle-eye by the above-described movement of theneedle-thread positioner, an amount approximating the distance from theneedleeye to the work, and to the fact that this drawing is permitted bythe previous loosening of the thread beyond the needle by thethreadpuller 34. and its cooperating mechanism. Attention is also calledto this length of thread to demonstrate that the device 41 is not athread-puller in the ordinary meaning of such term, as it does not drawthe thread sufiiciently for the restarting of the machine, this beingaccomplished by the thread-puller 3 L. WVith the various parts in thepositions thus described the work is either drawn along the work-supportto bring another portion below the needle or is drawn entirely from themachine. In drawing the work forward it is also moved diagonally in thedirection of the slot 54. The first trimming action is of course on theneedle-thread, which is out between the cooperating cutting portions ofthe cutter members 4:2 and 43, the cut end being retained between thecutter member 42 and the spring 46, as is shown in Fig. 3 of thedrawings, and leaving a cut end a, Fig. 5, above the work. The moving ofthe work being continued, the shuttle-thread is carried along throughthe slot 54 and enters the slot 50, this drawing of the shuttle-threadbeing in a degree restrained by the shuttle tension. The angle ofinclination between the shuttle-thread and the lower surface of the workchanges from the first practically vertical direction to approximatelythe angle shown in Fig. 2 of the drawings. At the tracted portion of theslot is gripped between the converging walls thereof slightly beforethat portion of the thread immediately below the work is brought intosevering contact with the edge of the cutter 51, and this positiveengagement of the shuttle-thread effects a positive resistance thereonto draw down the cut end of the needle-thread. The gripping of theshuttle-thread between the converging Walls of the slot 50 also holdsthe cut end of this thread drawn out for the restarting of the machine.

I do not limit myself to the particular constructions herein shown anddescribed, for it is understood that the parts and their combinationsmay be considerably varied without departing from the spirit of thisinvention.

Having thus described my invention, I claim as new and desire to secureby Letters Pat-.

ent

1. In a sewing-machine, a work-supp ort furnished with a slot, extendingfrom the needlehole, the converging edges of which slot form ashuttle-thrad-gripping device.

2. In a sewing-machine, a work-support comprising a throat-plate havinga needlehole and a slot extending therefrom, and a plate in which thethroat-plate is movably secured and having a slot with which the slot ofthe throat-plate 'is designed to register, and a thread-cutting devicepositioned in line with said slot.

3. In a sewing-machine, a work-supporting plate, having a slot, theconverging edges of which form a thread-gripping device, a cutteradapted to act on thread extending through said slot, and a throat-plateremovably secured to said supporting-plate and having a needle-hole anda slot extending from said hole and adapted to register with the slot insaid supporting-plate.

In testimony whereof I affix my signature in presence of two witnesses.

ROBERT L. LYONS.

Witnesses:

HENRY J. MILLER, ARTHUR E. DENISON.

